Much like those of Irish, Italian and German heritage before them, after several generations, Hispanics integrate to the point of disappearing.

If you go by the number of people who check the “Hispanic” box in US Census Bureau forms, people of Latin American descent make up 18% of the population. But, among the adult population, there are another 5 million, who don’t consider themselves Hispanic but descend from Latin America, according estimates from Pew Research Center.

Among the estimated 42.7 million U.S. adults with Hispanic ancestry in 2015, 89%, or about 37.8 million, thought of themselves as Hispanic or Latino, but the rest did not, according to Pew surveys. By the fourth generation, half those with Hispanic background no longer consider themselves part of the group.

This may be because Hispanics tend to marry non-Hispanics at a relatively high rate. Immigration from Latin America also has declined. Those trends, says Pew, “are distancing some Americans with Hispanic ancestry from the life experiences of earlier generations, reducing the likelihood they call themselves Hispanic or Latino.

When asked, those with Hispanic heritage who don’t consider themselves Hispanic say it’s because they have a mixed background (27%); they don’t have contact with their Hispanic relatives (16%); or they don’t speak Spanish or look Hispanic (15% and 12%, respectively.)

Nearly 60% of those who don’t identify as Hispanic say they would be taken for white by passers-by in the street; only 7% of them believe they are seen as Hispanic by others.

Tracking this previously unaccounted group, self-identified non-Hispanics with Hispanic ancestry, as Pew refers to them, has political and policy implications. Contrary to some public views, a large number of Hispanics do assimilate and no longer congregate in enclaves to preserve their language and culture.

This, of course, is the exact same experience of most other ethnic groups who emigrate to America, whether of Irish, Italian, German, or another heritage. Just like those groups, after several generations, Hispanics start integrating to the point of disappearing.